Double injection system with one nozzle



E. c. PELZ, JR.. ET AL DOUBLE INJECTION SYSTEM WITH ONE NOZZLE 6 6 z/gy??? 5%@ Y; S@ fN/ gy @Qges 52 S) F50 'Y c ,58 -E 32 54- FQ: 44 @22 54640 24/ wz IO Filed June 14, 1967 RUDOLF W 'I/////X///1/ /NVENTRS EDWARDC. PELZ, JR.

W. GU RTLER tried US. Cl. 239-453 6 Claims ABSCT F THE DISCLOSURE A fuelinjection nozzle having a plurality of orifices and valve meansassociated with the nozzle to permit independent injections through saidorifices at predetermined fuel pressures. The nozzle is designed toprovide a pilot spray through one orifice means and a main injectionthrough another orifice means.

This invention relates to a fuel injection device and more specificallyto a fuel injection nozzle having a plurality of orifices.

For certain applications it is desirable to have two fuel sprays into acombustion chamber which are independent of each other in time anddirection. This could be achieved by the use of two injection pumps andtwo injection nozzles, but the uneconomical aspect of this yarrangementis apparent, Accordingly, it is herein proposed to provide a fuelinjector device of simple construction in which two orifice means areprovided to inject fuel at diderent predetermined times and in differentpredetermined directions and using only one fuel injection pump.

It is a principal object of this invention to provide a fuel injectiondevice, having a plurality of orifice means each controlled by a-separate valve element.

Another object is to provide a fuel injection device which first caninject a pilot spray and then inject a main spray in response todifferent pressures of the liquid fuel in the injection device.

The above and other objects and advantages of the invention will be morereadily lapparent when considered in connection with the accompanyingdrawings in which:

FIGURE 1 is an elevation View partially in section of a fuel injectordevice showing the valves thereof in a closed position;

FIGURE 2 is an eleva-tion view of a portion of a fuel injection pump;and

FIGURE 3 is an enlarged view of a portion of the fuel injection deviceshowing the sleeve valve in an open position.

Referring now to the drawings wherein like reference characters in theseveral views represent the same parts, reference character designates afuel injection device and 12 Va portion of a fuel injection pump whichsupplies pressurized fuel to the injector device 10. The injection pump12 has a pumping plunger 14 actuated at its lower end by a cam (notshown). The plunger 14 moves up and down and :builds up enough pressureduring its upward stroke as viewed in FIGURE 2 to open a fuel deliveryvalve and force pressurized fuel through conduit 16 to the injectordevice 1t? into an inlet passage, through a pair of valves and throughspray orifices to the cylinder of an internal combustion engine withwhich the injector device is associated.

The injector device 1i) comprises a nozzle body 18 having an inlet fuelpassage 20 formed therein, a fuel chamber 22, a second fuel passage 24and a third fuel passage 26. The device 10 also includes first and-second orifice means 28 and 30, through which fuel is injected into thecylinder of an engine. The device 10 further inlii cludes a yfirst valvemeans in the form of a cylindrical sleeve valve member 32, forcontrolling the flow of fuel to orifice means 28 and a second valvemeans in the form of a needle valve 34 for controlling the flow of fuelto orifice means 30 and first and second compression spring -means 36and 38.

The injection `device 10 may be secured in the engine block by suitablemeans such -as the threads 40 formed on a portion of the nozzle body.The nozzle body may have formed therein Ia bore 42, somewhat larger indiameter than the needle valve 34 disposed therein to form 4thecircumferential passage 26 which communicates with the fuel chamber 22at its upper end and orifice means 30 at its lower end. A bore 44 isformed above the fuel chamber 22 to slidingly receive the sleeve valvemember 32. Pressurized fuel in the fuel chamber 22 exerts `an upwardforce on the sleeve valve 32.

The sleeve valve 32 is formed with a bore 46 to slidingly receive theneedle valve 34 therethrough. The sleeve valve 32 is also formed with=an enlarged head 48 at rthe upper end thereof to define a shoulder S0which seats in a counterbore 52 formed in the upper end of bore 44. Afuel duct 54 extends through the wall of the sleeve valve 32 at itslower end. Liquid fuel reaches this duct 54 through counterbore 56formed on the lower end of the sleeve valve 32. When fuel pressureacting on the lower end of sleeve valve 32 moves the latter upwardly,the duct 54 is brought into registry with fuel passage 58 which is incommunication with fuel passage 24.

The needle valve 34 has an enlarged portion 60 formed at its upper endwhich defines a shoulder 62 against which the upper end of sleeve valve32 is adapted to seat during its upward movement. This shoulder 62 actsas a stop for the sleeve member 32 to restrain its upward movement solong 'as the fuel pressure on the lower end of the sleeve valve is belowa predetermined amount. When the fuel pressure rises above suchpredetermined amount, the upward movement of the sleeve valve istransmitted to the needle valve 34 to raise the latter from its seat.The upper portion of the needle valve and the compression spring members36 and 38 are disposed in a .bore 63 in upper part of the' nozzle body.A radially extending flange 64 is formed on the upper portion 60 of theneedle valve 34 and spring means 36 and 38 act against opposite sides ofthis flange. The compression yspring means 36 surrounds upper portion 60and seats on the flange 64 and upper surface of sleeve valve 32. Iturges sleeve valve 32 toa closed position, i.e., seated on the shoulder50 to hold the fuel duct 54 out of registry with fuel passage 58 andpositioned below passage 38 as viewed in FIGURE 1. Compression spring 36is a weaker spring than compression spring 38 thus allowing the sleevevalve 32 to be raised by a relatively small fuel pressure withoutdisturbing the needle valve from its seated position. The compressionspring 38 is a relatively strong member and is `disposed between theupper side of flange 64 and a reaction member 66 seated in `a nozzlebody cap member 68. The latter may be threaded onto the upper part ofthe nozzle body. A leak-off channel `69 may be provided in the nozzlebody to carry leakage fuel back to the fuel supply reservoir (notshown). The lower end of the needle valve may have a valve face 70formed thereon to seat on a complementary valve seat 72 formed in thenozzle to con-trol the opening -to mlain injection orifice means 30.

Orifice means 28 may comprise a single orifice or a plurality oforifices in communication with fuel passage 24, and orifice means 30 maycomprise a single orifice or a plurality of orifices adapted to becontrolled by needle valve 34. The orifice means 28 is positioned todirect a certain amount of fuel into or close to a high temperaturesource. Its purpose is to provide a pilot injection to help ignite themain spray. The main injection is provided by orifice means 30, and thisorifice means 30 is directed into or close to the fiame created by thecombustion of the pilot injection. The two valves, sleeve valve 32 andneedle valve 34, open in succession in response to the differentpressures built up in an injection pump such as pump 12.

Injection pump 12 is the subject of copending application for U.S.Letters Patent, Ser. No. 646,033, filed on June 14, 1967. Injection pump12 will be described here only generally. The pump -12 comprises in parta housing 80, defining a bore 82 in which pumping plunger 14 is disposedfor reciprocating movement in response to the action of a cam (notshown), at its lower end. The pump 12 also comprises a fuel chamber 84adapted to be connected to and receive fuel from a fuel supply reservoir(not shown). A delivery valve 86 normally closed by the action ofcompression spring 88 is adapted to be opened by an increase of fuelpressure in a pumping chamber 90 wherein pressure is built up as theplunger 14 moves upwardly. With this increase in pressure, fuel underpressure is sent to the fuel injector device through conduit 16connected to the injection pump. It will be observed that the upperportion of pumping plunger 14 has a narrow notch 92 and a substantiallytriangular notch 94 communicating by passage means (not shown) in theplunger 14 with the pumping chamber 90. Spill port means, one of whichis shown at 96 in the housing 80, provides flow communication betweenthe fuel chamber 84 and the pumping chamber 90 whereby fuel fiows fromfuel chamber 84 to pumping chamber 90. When the plunger 14 movesupwardly, a shoulder 98 on the upper end thereof blocks the flow of fuelfrom the fuel chamber through the spill port means 96. At that point,pressure begins to build up in pumping chamber 90 and fuel is -forcedpast the delivery valve 86 against the force of spring 88 throughconduit 16 to the fuel injector device 10. The notch 92 is provided torelieve the pressure in the pumping chamber as it moves into registry4with spill port means 96. As the plunger 14 continues to move upwardly,a land 100 in the form of a helix between the notches 92 and 94 againseals off the spill port 96 and pressure in the pumping chamber 90continues to build up.

While the operation of the injector device is probably apparent from theabove description of its construction, a brief summary of its operationwill now be given. When the plunger 14 of the injection pump movesupwardly to the point where the shoulder 98 cuts off the spill portmeans 96, pressure is built up in the pumping chamber 90, openingdelivery valve 86 and sending pressurized fuel through conduit 16 to theinjector device 10. The pressurized fuel moves through inlet fuelpassage 20 to the fuel chamber 22 and acts on the sleeve valve 32 tomove it upwardly against the shoulder 62 on the needle valve. In doingso, the fuel duct S4 of the sleeve valve is brought into registry withfuel passage 5S and fuel is sent to orifice means 28 via passage 24.This occurs at a predetermined relatively low fuel pressure such, forexample, as about 1500 p.s.i., because the spring 36 is made relativelyweak. This provides a pilot spray to give a high energy source for themain injection. As the plunger 14 continues to move upwardly, the notch92 in the plunger registers with spill port means 96 and fuel flows fromthe pumping chamber 90 back to the fuel chamber S4, relieving thepressure in the system. Then spring 36 reseats the sleeve valve 32 onshoulder 50, closing off fluid communication with the fuel duct 58. Asthe plunger 14 continues to move upwardly, land 100 again blocks spillport 96 and pressure in the pumping chamber continues to build up. Theconstruction of the plunger is such that fuel pressure can now build upto a considerably higher amount such, for example, as 3000 p.s.i. Thisfuel pressure moves the sleeve valve 32 up against the shoulder 62 withsufiicient force to overcome the relatively stronger spring 38 and liftthe needle valve 34 from its seat 72 thus permitting fuel to passthrough orifice means 30. This is the main injection and the velocityand quantity of fuel pumped during this main injection generally will belarger than during the pilot injection. As the sleeve valve 32 moves upwith the needle valve 34, the lower edge of the sleeve valve closes offduct S8 feeding orifice 28. As the plunger 14 moves downwardly at theend of the pumping stroke, the pressure is decreased, of course, and thevalves 32 and 34 are reseated, and the cycle is then repeated.

It will be appreciated that the quantities of fuel to be injectedthrough each orifice means and the duration of the respective injectionsare independently variable. These can be varied by controlling thespring strengths of springs 36 and 38 as well as the notch formations inthe pumping plunger which provides for relief of pressure in the pumpingchamber of the fuel injection pump.

Thus it will be apparent that we have advantageously provided a fuelinjection device of relatively simple construction, which is capable ofproviding two injections of fuel through separate orifices independentof each other, one being a pilot or prespray and the other a maininjection. The device uses a minimum of parts, and, as can readily beseen, the parts are uncomplicated structures.

We claim:

1. In a fuel injection device adapted to receive pressurized fuel from asource of supply and to inject the fuel into an internal combustionengine, the combination cornprising: a nozzle body; first fuel passagemeans in said nozzle body adapted to be connected to a source ofpressurized fuel; first and second orifice means in said nozzle body forinjecting fuel into the engine; first and second valve means forcontrolling the iiow of pressurized fuel to said first and secondorifice means respectively; yieldable biasing means associated with saidfirst and second valve means to hold said first and second valve meansin a closed position; bore means in said nozzle body; second fuelpassage means in communication with said first orifice means and saidbore means; said first valve means comprising a cylindrical sleeve valveslidably disposed in said bore means, and adapted to have fluid pressureact on one end thereof, said first valve means including, first meanstherein for establishing fluid communication between said first fuelpassage and said second fuel passage means including, a fuel ductadapted to be placed in communication with said second fuel passagemeans in response to pressurized fuel acting on said sleeve valve.

2. A fuel injection nozzle for an internal combustion engine,comprising: a nozzle body having central bore means extendinglongitudinally thereof, said bore means partially defining a chamber influid communication with a source of pressurized fuel; first fuelejection orifice means in said nozzle body in fluid communication withone end of said bore means; first valve means operatively interposedbetween said first fuel ejection orifice means and said bore means forcontrolling the flow of pressurized fuel through said first fuelejection orifice means; second fuel ejection orifice means in saidnozzle body; recess means formed in a wall portion of said bore means;fuel passage means in said nozzle body providing fluid communicationbetween said second fuel ejection orifice means and said recess means;second valve means operatively interposed between said bore means andsaid recess means for controlling the flow of pressurized fuel throughsaid second orifice means, said second valve means including a valveelement disposed within said bore means and movable longitudinally withrespect to said nozzle body between a lfirst closed position whereinfluid communication between said bore means and said recess means isdisestablished, an intermediate open position wherein fiuidcommunication between said bore means and said recess means isestablished, and a second closed position wherein fiuid communicationbetween said bore means and said recess means is disestablished;yieldable biasing means associated with said first and second valvemeans for urging said first valve means closed and said valve element ofsaid second valve means toward its first closed position, said valveelement being responsive to the pressure of the fuel in said bore meansand movable to said intermediate open position upon the attainment offluid pressure in said bore means at a rst predetermined magnitude andmovable to said second closed position upon the attainment of uidpressure in said 4bore means of a second predetermined magnitude, saidrst valve means being responsive to the pressure of the fuel in saidbore means to open only upon the attainment of uid pressure in said boremeans of said second predetermined magnitude.

3. A fuel injection nozzle as set forth in claim 2, wherein said valveelement slidingly engages said bore means and includes a cylindricalsleeve-like end portion, said end portion covering said recess meanswhen said valve element is in its iirst and second closed positions,said end portion having a radially extending aperture formedtherethrough, said aperture being in radial registration with saidrecess means only when said valve element is in its intermediate openposition.

4. A fuel injection nozzle as set forth in claim 3, wherein said firstvalve means includes an elongated needle valve extending longitudinallythrough and engaging said valve element for relative sliding movement;and interengagng abutment means carried by said needle valve and saidvalve element Ifor limiting sliding movement of said valve element withrespect to said needle valve in one direction, said valve element beingin its intermediate open position when said interengaging abutment meansare in engagement and said iirst valve means is closed.

`5. A fuel injection nozzle as set vforth in claim 4, wherein saidneedle valve is formed with an enlarged end section;

and said interengaging abutment means includes the annular shoulderformed at the juncture of said enlarged end section and the reduceddiameter main body portion of the needle valve.

6. A fuel injection nozzle as set forth in claim 5, wherein saidenlarged end section of said needle valve is provided with a radiallyextending, annular ilange intermediate its ends; and said biasing meansincludes a first helically wound compression spring encircling saidneedle valve and having one end abutting said annular ange and itsopposite end bearing against said valve element of said second valvemeans, and said bearing means further including a second helically woundcompression spring encircling said needle valve and having one endabutting said annular ange and a stationary part of said nozzle body,said second spring exerting a relatively greater force on said annularflange than said first spring.

References Cited UNITED STATES PATENTS 3,339,848 9/ 1967 Geiger 239-533FOREIGN PATENTS 926,643 4/ 1955 Germany. 792,775 4/ 1958 Great Britain.

EVERETT w. KIRBY, Primary Examiner.`

U.S. Cl. X.R. 123-32.61; 239-533

